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(No Model.) 2 Sheets-Sheet 1. RP. WARNER.

ooNTRoLLRR ROLLER RoR RLRGTRIG GARS. No. 505,686. Patentedept. 26, 1893l mm n. ummmlrmililrun 1"* i R RR Wulnnmurllum l* I (No Model.)

E. P. WARMJR.` CONTROLLER ROLLER FOR ELECTRIC CARS.-

2 Sheets-Sheet 2.

Patented Sept. v26, 1893.

UNITED STATES PATENT OFFICE.

ERNEST P. `WARNER, OF CHICAGO, ILLINOIS, ASSIGNOR yTO THE WESTERNELECTRIC COMPANY, OF SAME PLACE.

CONTROLLER-ROLLER FOR ELECTRIC CARS.

SPECIFICATION forming part of Letters Patent No. 505,686, datedSeptember 26, 1893.

i Application filed June 21, 1892. Serial No. 437,505. (No model.)

To aZZ whom it may concern.-

Be it known that I, ERNEST P. VARNER, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a certain new and useful Improvement in Controller-Rollers forElectric Street-Railway Cars, (Case No. 50,) of which the following is afull, clear, concise, and exact description, reference being had to tothe accompanying drawings, forming a part of this specification. n

Myinvention relates to controller rollers for electric railway cars, andits object is to provide a controller roller that shall obviate the t 5trouble caused by the sparking between the adjacent conducting stripsand a consequent destruction of the insulating material between suchstrips and the loss of energy due to such sparking. zo In theaccompanying drawings-Figure 1 is a view of the roller with theconducting stri ps removed and showing a sectional view of some of thedisks of which the roller is built. Fig. 2 is a sectional view being asection on line 2-2 of Fig. 1, showing strip attached. Fig. 3 is a viewshowing the roller with conducting strips attached and fingers bearingthereon for carrying the current to and from said conducting strips,eight of the 3o fingers having been removed.

Like letters refer to like parts on the several figures.

The roller is built up of disks of slate or other insulating material.The disks are of 3 5 two sizes, the diameter of one set being greaterthan the diameter of the other. The larger disks a a and the smallerdisks b b are placed alternately upon a shaft provided with a feather fover which feather the disks slip, 4o keyways being cut therein. Thisarrangement prevents any rotary movement of the disks upon the shaft. Asleeve m is fastened to the shaft g by means of a bolt n passing througha hole bored through the shaft and 4 5 the sleeve, said bolt n beingheld in position by a cotter pin o. The sleeve m may be either separateor a part of the hub of the driving wheel by which the roller isrevolved. Against the sleeve fm, is placed the collar Z and upon 5o thisthelarge and the small disks aa and b ZJ are alternately placed, andupon the last disk a collar il is placed, and the nut 7s working upon athread cut on the shaft g on being screwed against said collar t',clamps the disks a (L and b b between the collars Z and z'.

The conducting strips are attached to the peripheries of the largerdisks a a by means of screws. I-Ioles are bored in the larger disks a aa short distance 'from the periphery and the ends counter-bored. Intothese holes Bab- 6o bitt-metal c or other soft metal is run and tits theholes and counter-bores. The metal that fills the counter-bores preventsthe working out of the metal e. Into this plug e is tapped a hole forthe screw d. In this manner the conducting strips may be firmly fastenedto the disk a. Upon these strips thus attached and suitably connected,the fingers r r are adapted to bear, the current passing from iinger tofinger through the connections between 7o the strips.

Previous to my invention controller rollers have been made by simplyfastening the conducting strips upon the surface of a cylinder made ofwood. When the potential difference between any two adjacent strips isunusual a spark is liable to be formed between the strips and this sparkfollowing the surface of the cylinder chars it, thus forming a carbonconductor between the adjacent strips and in 8o consequence causes awaste of energy. This formation of a carbon conductor has in cases beenobviated by the placing of strips of slate or other non-combustibleinsulating material betweentheconductingstripsbutthis,though preventingwaste by the leakage of current by the carbon conductor, does notprevent the passage of a spark when the potential is unusual, and theconsequent loss thereby. When the roller is constructed of disks, in 9othe manner set forth, the difference of potential between anytwoadjacent strips must be suiiicient to break down the air medium 'a ccFig. 1 or to follow along the surface of the disk by the line u o to 0c.To obviate danger 95 from the first cause, the disks maybe placed atsuch a distance that the difference of potential may never be greatenough between any two strips toeause a breaking down of the air spaceor maintain a persistent arc. As roo the distance u 'o w :c may be madeconsiderable by making the difference in the diameters of the diskslarge there will be no danger of the spark passing along the surfacesrepresented bythe line u fu w unless, probably, in the case of the disksbeing covered with 5 moisture, in which case, however, the mere passageof the spark will cause the vaporization of the moisture and theconsequent extinguishment of the spark.

Having thus described my invention, what io Iclaim as new, and desire tohave secured by Letters Patent, is-

1. In' a controller roller for electric railway cars, the combinationwith a shaft g, carrying a feather f, of disks of insulating material i5placed upon the said shaft, keyways being cnt therein to prevent therotary motion of the disks relatively to the shaft, of the sleeve mfastened to the shaft g and collars Z and t', of the nut la adapted toclamp the disks between zo the collars Z and t', the adjacent disksbeing of different diameters, the soft metal plug c fitting thecounter-bored holes in the disks a a, holes being tapped therein toreceive the screws d d to fasten the conducting strips cc z 5 to thedisks a a, substantially as specified.

2. In a controller roller for electric railway cars, the combinationwith large and small disks of insulating material placed alternatelyupon a shaft, of means for clamping said disks 3o upon said shaft, andmeans for preventing any rotary motion of said disks relatively to saidshaft, and conducting strips attached to the peripheries of said largerdisks, substantially as specified.

3. In a controller roller for electric railway cars the combination withconducting strips, of screws passing through said conducting strips andfitting in tapped holes in soft metal plugs, which plugs are fitted intoholes near the peripheries of thc large disks of the roller, the holesbeing counter-bored, whereby the plug is held firmly in position,substantially as specified.

4i. In a controller roller for electric railway cars, the combinationwith the conducting contact strips ot' spring fingers resting thereon,said conducting contact strips being supported upon the peripheries ofdisks of insulating material, said disks being mounted upon a shaft andadapted to rotate therewith, and disks ot less diameter separating saiddisks carrying the contact strips, substantially as described.

In witness whereof l hereunto subscribe my name this 11th day of May, A.D. 1892.

ERNEST P. VARNER.

Witnesses:

W. CLYDE JONES, M. JEANE TALLETT.

